Grinding machine-carriage reciprocating mechanism



8- 1943: c. c. ALVORD 2,327,486

I GRINDING MACHINE CARRIAGE RECIPROCATING MECHANISM Filed July 5, 194-1 4 Sheets-Sheet l awe/Moe G'HARL. E5 U. A LVURIJ Aug. 24, 1943. c, ALVR-D 2,327,486

GRINDING MACHINE CARRIAGE RECI PROCATING MECHANISM I Filed July 5, 1941 4 Sheets-Sheet 2 :EHARLES C. A LVDRJD WMm-mm WW Patented Aug. 24, 1943 GRINDING MACHINE-CARRIAGE nnolrno- CATING MECHANISM Charles C. Alvord, W orceste1-, Mass, assignor to Norton Company, Worcester, Mass, a corporation of Massachusetts Application July 5, 1941, Serial No. 401,071

10 Claims.

, The invention relates to grinding machines, and more particularly to "an electrically driven grinding wheel traversing mechanism.

One object of the invention is to provide a simple and thoroughly practical motor driven traversing mechanism for a grinding wheel carriage. Another object of the invention is toprovide an electrical control mechanism for .a grinding wheel carriage whereby .the movement of the grinding wheel carriage may be readily controlled, that'is, the carriage either started to ward the right or toward the left, .inched or' jogged toward the right or toward'the left, or stopped, as desired, by a push'button .control system. Other objects will be in part obvious or l-.l of Fig. 2, through a grinding wheel carriage, showing. the electrically driven traversing and reversing mechanism therefor;

Fig. .2 is a cross sectional view, taken approximately on the line 22 of Big. 1; V

. Fig. 3-is a fragmentary sectional view, taken approximately on the. line 3-'-3 of Fig. 1;

Fig. 4 is electrical wiring diagram combined-withan: elevation of the reversing switches and, their actuating mechanism;

Fig. 5 is afragmentary front elevation of the, reversing control mechanism, on an enlargedscale; i

Fig. dis a fragmentary -plan View of the mesh anism. as shown in 5;

Fig. 7 is a fragmentary plan view of the mechanism as shown in Fig. 5;

Fig. 8 is a fragmentary sectional view, on an enlarged scale, taken approximately on the line 8--3 of Figs. 5' and '7;

Fig. 9 is a fragmentary sectional view taken approximately on the line 9-9 of Fig. 8;

Fig. I is a fragmentary horizontal sectional view, taken approximately onthe line IO-40 of Fig,

Fig. 11 is a fragmentary sectional view, on an enlarged scale, taken approximateiyon the line ll-H of Fig. dogs; and f V Fig. 12 is a fragmentary vertical sectional view, on' an enlarged scale, taken approximately on the line 12-42 of Fig. '7, through one of the V reversing dogs.

A portion of a grinding machine has been illustrated in they drawings, comprising a base 20' which supports a' longitudinally reciprocable. grinding wheel carriage 2| on a V-way 22 and a flat way 23. A rack bar 24 extendslongitudinal; ly relative to the base 20 and is fixedly mounted thereon. i

Amotor driven carriage reciprocating mecha nism is supported onthe carriage 2| within a casing or housing 25. A reversible electric motor 26 is mounted on an adjustable pivotally mounted motor support 21. The motor support 21 is supported at oneend on a' rock shaft 23 whi'ch in turn is fixedly supported 'on the upper portion of the casing 25. An adjusting screw'29 is screw threaded through the motor Sup ort 21". and bears against a lug 30 projectingfrom the casing 25 by means of which the motor 26 may adjusted to tensionthe drivingbelts, The motor 2 5 is provided with an armature shaft 31. having a multi-V-groove pulley 32 mounted thereon. The pulley 32 is connected by a plural ity of V-belts 33 with a multi-V-groove pulley 34 which. is supported on a rotatable shaft 35. The shaft 35 is journalled in a bearing 36 carried by the casing 25 A pinion 31 is formed on the inner end of the shaft 35 which meshes with ,a gear 38 which is rotatably supported on a shaft 39. The shaft 39 is journalled in bearings 43 and 4| which are supported by ,thecasing 25. The gear 38 is keyed to a rotatable sleeve 42 which is formed with clutch teeth on its lefthand end (Fig. 1) and is arranged to be clutched to the shaft 39 bymeans of a' slidably keyed clutch member 43 which is actuated in a manher to be hereinafter described.

f A pinion 44 is formed adjacent to the lefthand end of the shaft 39 and meshes with a gear 45. The gear '45 is supported on a bearing sleeve which is in turn rotatably supported on a rotatable shaft 41. Theshaft 41 is journalled in bearings 48, 49 and 50 in the housing 25. A worm 5| is formed'integral with a reduced end portion 52 of the shaft 41. The worm 5| meshes with a worm gear 53 which is keyed on a rota-table shaft 54. The shaft 54 is 'jour-nalled inbearings 55, it and 51 which arein turn supported by the casing 25. A small gear 58 is'formed in teg'ral' with the shaft 54 and meshes with-a gear 5, through one of the reversing rotary motion of the motor shaft 3| in either di-' rection will transmit a rotary motion to the gear 64 through the gearing previously described so that the gear 64 meshing with the rack 'bar 24 will impart a longitudinal traversing or reciproeating movement of the grinding wheel carriage 2 I.

In a grinding wheel traversing mechanism of this type, it is desirable to provide a variable speed mechanism for traversing or reciprocating the carriage 2|. The mechanism previously described including the pinion 44 meshing with the gear 45 serves to transmit a relatively slow movement to the carriage 2|. The gear 45 is rotatably supported on the shaft 41 and in the position shown in Fig. 1 the gear 45 is locked to the shaft 41 by means of a slidably mounted clutch member I which is keyed to the shaft 41. The clutch member I0 is provided. with a large gear II and a small gear I2. If it is desired to obtain a'fast speed of reciprocation of the carriage 2|, the clutch member I0 is moved toward the right (Fig. 1), disengaging the clutch teeth from engagement with clutch teeth formed integral with the gear 45, and is moved toward the right so that the gear I2 is meshed with the gear 30, in which position the drive from the motor 26 through the gear 3-8 will be transmitted directly to the gear I2 and the shaft 4Twhich is in turn transmitted to the gear 64 heretofore described.

If an intermediate speed of the carriage 2| is desired, the clutch member I0 is moved toward the right (Fig. .1) so that the gear 'II meshes with a gear I3 which is keyed to the shaft 39, in which position the power of the motor 26 will be transmitted from the shaft 39 through the gear I3 and the gear II to rotate the shaft 41 which in turn is transmitted 'throughthe gear mechanism above described to rotate the gear 64 at an intermediate speed to cause an intermediate reciprocatory speed of the grinding wheel carriage 2|..

A manually operable clutch shifting mecha'-' nism. is provided for the clutch I0, comprising a yoked member I5 which isfixedlymounted on one end of a slidably mounted rod I6. The rod I6 is slidably journalled in bearings 11 and I8 formed in the casing 25. A rack bar I9 is formed on the rod I6 adjacent to its left-hand end (Fig. 1). A gear 80 which is keyed to a rotatable shaft 8| meshes with the rack I9. The shaft 8| is journalled in'a bearing 82 formed integral with the casing 25. The shaft 8| supports on its outer end a manually operable hand wheel 83 by means of which the yoked member I5 may be readily shifted from the slow speed position illustrated in Fig. 1 to mesh either the gear II or the gear I2 with the gea r I3 or the gear 38, respectively, so as to produce either a fast, intermediate or slow reciprocatory speed of the grinding wheel carriage 2 I.

In the operation of this carriage traversing mechanism, it is desirable to provide a manually operable control for use in setting up the ma: chine whereby the carriage 2| may be traversed The gear manually when desired. In case it is desired to traverse the carriage 2| manually, a yoked member is provided for actuating the clutch member 43 whereby the gear 38 may be declutched from the shaft 39. The yoked member 85 is supported on the right-hand end of a slidably mounted rotatable shaft 86. The shaft 86 is rotatably and slidably journalled in bearings 81, 88 and 89 (Fig. 1). A manually operable hand wheel 93 is keyed to the outer end of the shaft or rod 86.

A gear 9| is keyed to the rod 85 and is arranged to be thrown into mesh with a gear 92. The gear 92 is rotatably supported on a stud 93 which isfixedly supported on a downwardly extending rib 94 of the casing 25. When it is desired to disconnect the power and to provide a manual traverse of the carriage 2|, the hand wheel is manually moved toward the left (Fig. 1), which movement shifts the shaft 86 toward the left during which movement the yoked member 85 throws the clutch member 43 out of engagement so as to declutch the gear 38 from the shaft 30. Continued movement of the shaft 86 toward the left throws the gear 9| into mesh with the gear 92. In this position of the gears, a manual traverse of the carriage 2| may be obtained by rotation .of the manually operable hand wheel 90 which transmitsa rotary motion through the rod 86, the gears 9|, 92 and 13, the shaft 36, the pinion44, the gear "45, the shaft 41, the worm 5|, the worm gear 53, the shaft 54, the gear 58, the gear 59, the pinion 63; and the gear 64 to cause the gear 64 to roll 'in mesh with the fixed rack bar'24 and thus transmit a longitudinal traversing movement to the carriage 2|. It will, be readily apparent from the foregoing disclosure that the direction of rotation of the manually operable traverse wheel 90 will determine the direction of traversing movement of the carriage 2| relative to the base 20.

A reversing control mechanism is provided on the' carriage 2| for controlling the length of the reciprocatory stroke of the carriage and the reversing of the carriage driving motor 26. A rotatable reversing control plate I00 is provided which is rotated by and in timed relation with the longitudinal reciprocating movement of the carriage 2| and is arranged to control the revelsible motor 26 so as to provide the desired and predetermined reciprocatory movement of the carriage 2|. A pair of reversing dogs IOI and I02 are adjustably supported by clamping T- bolts I03 and I 04, the heads of which are slidably positioned within a T-shaped slot I05 formed adjacent to the periphery of the plane side face of the reversing plate I00. It will be readily apparent from the foregoing disclosure that the reversing dogs IOI and I02 may be adjusted into any positions around the periphery of the reversing plate I00 so as to facilitate adjustment of the length of the reciprocatory stroke of the carriage 2|.

The reversing plate I00 is keyed to a rotatable sleeve I 06 (Fig. 1) which is journalled in bearings I0I'and I08 which are supported in fixed relationship with the housing 25. The plate I03 together with the sleeve I06 are connected by a reduction gear train with the carriage driving mechanism. The reduction gear train is so designed that during a maximum reciprocatory stroke of the carriage 2|, the reversing plate I00 will rotate less than one complete rotation. A worm gear I09 is keyed to the inner end of the sleeve I58; The-worm gear I419 meshes with worm. III) which, .as illustnated is iormedintegral witliarotatable shaft II I. The-shalt IN- is joumalled in bearings H2 andz'li'3 which supported in the housing 25; A gear 'II4-,-(;Fig. 2) pinned togrolnte with the worm l m and shaft. II I..v The gear H4 meshes with a gear Hi5 which is fixedly mounted relative. tothe large worm wheel 53; It willlbe readily apparent from the foregoing disclosure that when the, wormgear 534s rotated: by the-worm .5I- tomeciprocate the-carriage 2 I-, a cotarymotion will be imputed through the gear I I-5;gthe gear I'I4 ,.the worm Md, and the worm gear I09 to'sotatcthe sleeve I185 and thereversing plate ma which carries therevers-ing dogs I01 and H321 I A ieversing' lever I is pivotally supported on acylindricalhub surface I2I whichis fixedly mounted relative-- to; .thecasing or housing: .25: A manually'openable handle Iiljssfixedly mound edzontheuppcrenduof: the: lever I520. The 'reversing: lever IZI serves as asupportvfor a pair of detents I13 and 1-24; The detents I23 and I24 are formed integral with. adjustably "positioned slide blocks. I25 and: 125, .itespactivelyu which are held in adjustedposition onzthe lever I28 by means of clamping nuts I21 and. I25. Thaclamping nuts Illand IZB amerscrew'threaded onto studs I 28 and $30,, respectively. which are fixedly supported. 011112118. lever 12D and pass through elongated slots I31! and. I52,.respectively; in the adjustabliy positioned blocks I25 andv I252, respectively. Adjusting. screws. I33 and: .I 34 are screw threaded into the adjustable blocks: #25: and I26, respectively, and; haverthein heads: rid ing in grooves I35 and I36 formedzin an. arm I31 whichis fixedly mounted? adjacent to the upper end of the reversing lever I20 to iacili tate independent adjustment of-the detents I25. and 124 relative to thelever I22. It will be readily apparent from the: foregoingnisclosure that by loosening the clamping nuts IZ-I: ammo andadjusting the screws I35 and I:34;;the blocks I25 and I26 together with the detentI-Qii and I24, respectively, may be readily and. precisely adjusted relative to the lever I 22 as desired, after. which they may be clamped in adjusted-position bytightening the clamping nuts I2 1and 12-8..

Each of the dogs I01 and: H32 is provided withpivotally mounted. levers I40. and HI whichlare supported on studs I 42 andqldii, respectively... The studs I42 and. R53 are fixedly supportedon the reversing dogs IN and: M22... The ends: of the dog levers MI! and MI are arranged'in the path of the detents I23 and I24, respectively,,.so that when. the reversing. plat-e 90 is rotated ineither direction, the rotary motion thereof. will continue untileither' the end of the dog. lever I40 or thedog lever MI engages-the detent I13 or the detent I24, respectively. to 'rock the re-- versing lever .I 2%) to change the direction of trav-. ersing movement of the carriage-H a manner to be hereinafter described. The dog levers I64!- and MI are biased to an operating position by tension springs which are interposed between the dogs IOI and H32. and the dog levers I40 and I'M, respectively. A pair of manually operable knobs I and I 45 are fixedly mounted on the dog levers I40 and I=4I,,respective1y; by means of'whichthe dog levers I40 and. MI: may be depressed-,,that. is, their operative ends moved toward the periphery of the reversing plateIilU so that they are out of the path of thedetent I23. on I24, re-

spectively, thus allowing theareversing plate. IBIL to rotate beyond its normal. movement, when desired, without actuating the reversing: lever 128i A: pair o! normally closed limit switches 15' and IiI: areprovided: for controlling the reversal of the motor 26 so as to reverse the direction of travel.- of. the grinding wheel carriage ZI asidesired;v The limit switches I53 and; I5I are-psovided' with actuating knobs I52 and I53 eachrof which-provided with elongated slots or notches I 54 and I55, respectively. A pair of pivotally mounted levers I56 and I251 are supported on relatively fixed studs I58 and I59, respectively; lower ends of thelevers His-and I51 are pro? vided with pins I53 and I54, respectively, which ride within theslots I54:and1 I55, respectively.

The levers I56 and I51 are pnefembly formed as bell crank levers each of which is-provided'with a. horizontally extending short arm IuZ-and I63, nespectively. Theshortarms- I62 and I53 are provided. with adjustable stopscrews I64 and. N5 respectively, whichare arranged to engage stop lug-s. I65- and .161 so as tolimit the swinging motionof the bellcrank leversIiG and I51; Apair of tension springs wand .I 69" are connected between-the short arms. I52 and I563, respectively, and brackets HI).- and I'll, respectively,which are fixed ielative tothe housing. 25. Thesprings H38 and I59 sen-ve normally tohold. the stop screws I54 and I65 in engagement with. the lugs I56 and I51, thus maintaining the downwardly 1 extending arms or levers I55. and t5] lathe-position. illustrated in Fig. 4 in maintain the. limit switches. .l.5fl and I51 in .aclosed position.

it is desirable to connect the limit switches I50 and I.5.I- so that they may be automatically actuated by movement of thereversing lever I25; A link. I15 isprovided to interconnect the reversing. lever I20 with. the lovers I55 and. I57, respectively. A pin or stud I15 is fixedly supported. onthe reveizsings lever I2 0. and: rides within an elongatedslotlll. formed the link, I 75. A stud I18 carried by the lever I56 and anstud I19. carried by tliclever I51 ride within elongated slots I l'and I8;I,.r.espectimely,.iormed in-.-t-he-link I15. As illustratedin Fig. 10,.the studs I 73 and I19 are positioned. to engage the outer ends of the elongated slots. I130 and- I3I, respectively. This position of thestuds may be readily obtained by adjustment of. the stop screws I64 and H55,- respectively. It. will be readily apparent from-- the foregoing disclosure that due to. the lost motion facilitated by the elongated. slots I and I8I9, the reversing lever I20 may be moved either in a clockwise or in a counterclockwise direction, during which movement only one of the switches- I50 or I'5I' is. actuated". Due to the tension of the springs I'BB and I69, the levers I55 and I51 for actuating the switches I50. and ISI, respec-- tively,. are normally held in a central position, thusrmaintaining the reversing lever I20. in a central position with both of the limit switches closed; V

A diagrammatic illustration has been shown.

in Fig 4,..showing the control mechanism for'the reversible motor 26-. Electric power is supplied from an. outside source, such as represented by; A manually adjustable;

the power lines I35. fheostat I86 is provided for regulating the speedof the motor 25 whereby the speed of traverse or reciprocation of the grinding wheel carriage 21 may be readily adjusted as desired; A- plural'ity of push button switches are provided for controlling the motor 26.. A pair of push but ton. switches I81 and. I88 are provided for start-- ing. the motor 25 so as totraverse the carriage- 2I toward the legft or toward the right, respec tively. Similarly, a pair of push button switches I89 and I99 are provided whereby the motor 26 may be inched or jogged to move the carriage 2| toward the left or toward the right, respectively, in positioning the carriage and the grinding wheel supported thereby. A push button switch I9I is provided to stop the traverse or reciprocation of the grinding wheel carriage 2| at any time.

A control relay switch I92 is provided for controlling a magnetic relay type switch I 93 for producing a movement of the grinding wheel carriage 2| toward the left or to control a magnetic relay type switch I94 which controls the movement of the grinding wheel carriage 2| toward the right; g I

' If it is desired to start the movement of the carriage 2| toward the left, the start left push button switch I8'I is closed, which movement energizes and actuates the'control relay I92 and closes a circuit which energizes and actuates the magnetic relay switch I93 to start the motor 20 so as to traverse the carriage'ZI toward the left. Similarly, if it is desired to start the movement of the carriage toward the right, the start righ push button switch I88 is closed to energize and actuate the control relay I92 and closes a circuit which energizes and actuates the magnetic relay type switch I94 to start the movement of the carriage 2| toward the right.

The control relays I 92 together with the relays I93 and I94 are interconnected with the push button switches I 81 and I88 so that when it is'desired to start the table moving toward the left, the push button switch IB'I is closed, that is, moved toward the left (Fig. 4), which movement closes a circuit to energize the control relay I92 and at the same time to energize the relay I93 so as to start the motor 20 in a direction to traverse the work carriage toward the left. The closing of the magnetic relay I93 opens a circuit to render the relay I94 inoperative during the traversing movement of the carriage toward the left. The carriage continues its movement toward the left until the dog mechanism previously described opens the limit switch I-5I so as to break the circuit to deenergize the relay I93 which operates to energize the relay I94 which reverses the current to start the motor 25 in the reverse direction so as to produce a reversal in direction of movement of the grinding machine carriage.

The inch control buttons I90 and I89 for movement of the carriage toward the right or toward the left, respectively, are connected directly to operate either the relay I93 or the relay I 94 to rotate the motor 28 in the desired direction so as to inch the carriage a predetermined distance when desired. The inching push button switches are effective only while the push button is maintained in a closed position to hold the relays I93 or I94 closed. After the carriage has once been set in motion by the start-left or start-right buttons I81 or I88, respectively, the carriage continuously reciprocates as governed by the limit switches I50 and I5I which are controlled by the dog and reverse lever mechanism above described.

Similarly, if a short adjustment is desired to position the grinding wheel carriage 2|, this may be accomplished by closing the inch right push button I90 or the inch left push button I89 to inch or jog the carriage ZI lengthwise relative to the base 20. At any time during the operation of the grinding machine, the machine may be 7 stopped by actuating the "stop push button I9| which opens the circuit to stop the motor 26 and thereby to stop the longitudinal reciprocatory movement of the grinding wheel carriage 2|.

After the carriage 2| has been set in motion by closing either the start left switch I81 or the start right switch I89, the carriage 2| is then under the automatic control of the normally closed limit switches I50 and I5I which are successively and automatically opened at the ends of the carriage stroke as governed by the adjustable re versing dogs IOI and I02. When the reversing plate I00 rotates in a counterclockwise direction, the dog lever I 4| of the reversing dog I02 will engage the detent I24 to move the reversing lever I20 in a counterclockwise direction. This movement serves to open the normally closed limit switch |5I which operates through the control relays I93 and I94 to reverse the direction of rotation of the motor 20 so as to start the carriage 2| moving in the reverse direction until the dog lever I40 of the reversing dog IIII, moving in a clockwise direction, engages the detent I23 to rock the reversing lever I20 in a clockwise direction (Fig. 5). This movement serves through the link I and the lever I56 to open the normally closed limit switch I50. The opening of the limit switch I59 serves to actuate the control relays I93 and I94 so as to again reverse the direction of rotation of the motor 26, thus stopping the movement of the carriage in one direction and starting it in the reverse direction. The length of the reciprocatory stroke of the carriage 2| is govened by the adjustment of the reversing dogs |0| and I02 about the periphery of the reversing plate I 00. It will be readily apparent from the foregoing disclosure that the reversing lever' I 20, except during reversal, is maintained in a neutral or central position by the springs I68 and I69 so that both of the normally closed limit switches I50 and lil are normally maintained in a closed po sition so as to facilitate inching the carriage 2| either toward the right or toward the left by closing the push button switches I89 or I99, respectively. .Theoperation of this improved carriagere: ciprocating mechanism will be readily apparent from the foregoing disclosure. Assuming the gear driving mechanism has been adjusted to give the desired speed to the carriage 2 I, it is merely necessary to close the push button switch I81 or I88 to start the reversible electric motor 26 to traverse the carriage 2| either toward the left or toward the right, depending upon which push button switch is actuated. The closing of either of the start buttons I8'I or I88 operates through the control relay I92 to actuate either the relay I93 or the relay I94 which control the direction of rotation of the motor 26 so that the carriage 2| will start its reciprocatory movement in the desired direction. In setting up the machine, it is frequently necessary to inch or jog the grinding wheel longitudinally relative to the base to position it relative to the work piece to be ground.

Due to the construction of the reverse control mechanism, except during the period of reversal, the reversing lever I20 is maintained in a vertical or neutral position by means of the action of the springs I68 and I69, as previously described. In this position both of the limit switches I50 and |5I remain closed. In order to inch or jog the carriage 2 I, it is merely necessary for the operator to actuate the "inch right push button I99 or the inch left push button I09, which movement fthrough :the relays 19:3 and a! instantaneously .to start :the reversible motor :25 either in one direction orlthe other to transmit an inching or dogging movement to the carriage '21 :without the :IIECGSSitYDf havingto shift .the reversing filever 112 0. :inching .or' jogging movement may" be obtained either toward :the' right or toward the left in any position of ithe carriage 2| exceptat the ends'lofi thecar riage stroke duringtheperidd of-reversal. If during a grinding operation it is desirable .and necessary to :stopthe traversing movement-, of the carriage 21, :this' may be accomplished iby .aetuatingtithe stop push-button switch 1:91 which serves to stopthe rotation of the reversingmotor 25.

ill; willthusbe :seen thatithere has "beenproe vided by thi :invention apparatus-in which! the various objects hereinabovie set forth .together with many thoroughly practical advantageslare successfully achieved. 'As many possible .em bodiments may be madev of a-tlte aboveiinvention and. as many changeslmightibe madeinthevembodiment above isetrortl n it is to: be. understood that alLmattenhereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. In a grinding machine having a longitudinally movable carriage, a reversing control mechanism therefor including a pivotally mounted reversing lever, a rotatable control wheel which is rotated by and in timed relation with said carriage, adjustable reversing dogs on said wheel to engage and actuate said lever, a pair of switches each having an actuating lever, and lost motion connections between said switch levers and said reversing lever whereby one of said switches is actuated when the reversing lever is shifted in one direction and the other of said switches is actuated when the reversing lever is shifted in the other direction.

2. In a grinding machine having a longitudinally movable carriage, a reversing control mechanism therefor including a pivotally mounted reversing lever, a rotatable control wheel which is rotated by and in timed relation with said carriage, adjustable reversing dogs on said wheel, adjustable detents on said reversing lever which are engageable by said dogs, a pair of switches each having an actuating lever, and lost, motion connections between said switch levers and said reversing lever whereby one of said switches is actuated when the reversing lever is shifted in one direction and the other of said switches is actuated when the reversing lever is shifted in the other direction.

3. In a grinding machine having a longitudinally movable carriage, a reversing control mechanism therefor including a reversible electric motor, a pivotally mounted reversing lever, rotatable control wheel which is rotated by and in timed relation with said carriage, adjustable reversing dogs on said wheel to engage and actuate said lever, means including a pair of switches to control said motor each having an actuating lever, connections between said reversing lever and said switch levers whereby one of said switches is actuated when the reversing lever is moved in either direction, a pair of jogging switches which are connected to jog said motor in opposite directions, and means normally'to maintain said reversing lever in a central position so that the motor may be jogged in either direction.

4. In a grinding machine having a longitudinally movable carriage, a reversing control mechanismgthereiordncl-ddinga revegsibletelectric tor, a pivdta-llyi mounted ,reversing- :levenlairotah ablexcontrol .wheelwhich de rotated-by in timed ,relationnwith .said vxisztrrialna, m l-jitstable re: versipg idogs on-rsai'd wheel toiengaxenndiaiotuate said lever, means including a Dainofswitches to controllsaidmotor each xluving aniaotuatiiig le= lest motion cc ines en bstwd nlsa d revers ing :lever and saidswitch-1 kev ers whereby (one lot said switchesisactnatedwhensthe reversing lever is nevediin ,either direction; a pair ,oi fleecing switches -,which are ,cennecte'd dog; said ,metor opposite directions; mean-s normally do maintain tsaid reversing lever in a central ,p -i tion so i that; the: motor hie jogged in-leitl'ieri direction.

anti-n a grinding machine barricaded-precis tic-.carriasa; means sinclyningia treversiblemctar to reciprocate saidcairriasria pivotalit reversin lever, .a rotat ble: control is ,onerativelylconnec ed-to ibez rotated-rbysands-in timed ,relatibn vwith z-the '.-loneitudina1'-. ovemm of the carriaeesadiustable onlsaie wbeehto ngage and lactnate said ,-reversi-n's*;lever, ,means including a pair of limit switches each being connected to control rotation of the carriage driving motor in one direction, an actuating lever for each of said switches, a link operatively connecting said switch levers, springs normally to hold said levers with the switches in a closed position, connections between said reversing lever and link whereby movement of said reversing lever in either direction serves to actuate one of said switches to reverse said motor and carriage, and means including a right-hand and a left-hand jogging switch for said motor and carriage, said reversing lever being normally maintained in a central position with both of the limit switches closed so that the motor and carriage may be jogged in either direction by actuation of the jogging switches.

6. In a grinding machine having a reciprocable carriage, means including a reversible electric motor to reciprocate said carriage, a rotatable control wheel which is rotated by and in timed relation with the movement of said carriage, adjustable dogs on said wheel, a pivotally mounted reversing lever which is actuated by said dogs, means including a pair of switches each being connected to control rotation of the carriage driving motor in one direction, a link operatively connecting said switches, lost motion connections between said link and switches, and connections between said reversing lever and link whereby movement of said lever in either direction serves to actuate one of said switches to reverse the motor and movement of said carriage.

7. In a grinding machine having a reciprocable carriage, means including a reversing motor to reciprocate said carriage, a rotatable control wheel which is operativeiy connected to be rotated by and in timed relation with the longitudinal movement of said carriage, adjustable dogs on said wheel, a pivotally mounted lever, said dogs being arranged to engage and actuate said lever, means including a pair Of limit switches each being connected to control rotation 01' the carriage driving motor in one direction, an actuating lever for each or said switches, a link connecting said switch levers, springs normally to hold said levers with the switches in a, closed position, and connections between said reversing lever and link whereby movement of the lever in either direction serves to actuate one of said switches to reverse said motor and carriage.

8. In a grinding machine having a reciproca ble carriage, means including a reversible motor to reciprocate said carriage, a rotatable control wheel which is operatively connected to be ro tated by and in timed relation with the longitudinal movement of the carriage, adjustable dogs on said wheel, a pivotally mounted reversing 1ev 1', said dogs being arranged to engage and act ate said lever, adjustably mounted detents on said reversing lever which are arranged in the path of said reversing dogs, means including a pair of switches each being connected to control rotation of the carriage driving motor in one direction, an actuating lever for each of said switches, and lost motion connections between said switch levers and said reversing lever whereby movement of the reversing lever in either direction serves to actuate one of said switches to reverse said motor and carriage.

9. Aginding machine carriage reversing control mechanism including a pivotally mounted reversing lever, a rotatable control wheel, adjustable reversing dogs on said wheel, adjustable detents on said reversing lever which are engageable by said dogs, a pair of switches each having an actuating lever, a link connecting said levers, connections between said link and said reversing lever, and lost motion connections between said link and each of said switch levers whereby one of said switches is actuated when the reversing lever is shifted in one direction and the other of said'switches is actuated when the reversing lever is. shifted in the other direction.

10. A grinding machine carriage reversing control mechanism including a pivotally mounted reversing. lever, a rotatable control wheel, adjustable reversing dogs on said wheel, adjustable detents on said reversing lever which are engageable by said dogs, a pair of normally closed switches each having an actuating lever, a link connecting said levers, connectionsbetween said link and said reversing levers, and 10st motion connections between said link and each of said arms whereby one of said switches is opened when the reversing lever is shifted in one direction and the other of said switches is opened when the reversing lever is shifted in the other direction.

CHARLES C. ALVORD. 

